(a) Field of the Invention
This invention relates to an apparatus for quickly and continuously producing Braun tubes of an accurate shape by arranging each glass plate between a male mold and female mold, intermittently moving it through a heating molding chamber and depressing and undepressing the male mold whenever it stops in a fixed position in the heating molding chamber.
(b) Description of the Prior Art
In an already known method of producing glass bulbs for Braun tubes in a glass melting furnace, taking out a fixed amount of a molten glass block and putting it into a metal mold to mold it, a highly skilled technique is required, such large related equipments as the melting furnace, taking-out device, metal mold, rotary pressing device and gradually cooling device are required and are made workable by using a precise controlling device and therefore the cost of producing bulbs is high. There is also seen an apparatus wherein, in order to eliminate such defects as are mentioned above, a glass plate is arranged between a male mold and female mold mounted on a rotary endless belt and is slowly passed through a heating chamber and the thus softened glass plate is made to follow the inside surface of the female mold by the self-weight of the male mold so as to be molded. In such method, as the glass plate is molded only by the fall of the male mold due to its self-weight, it is difficult to quickly and smoothly obtain products of a predetermined thickness and accurate shape.